JP2577299Y2 - Flyback transformer - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flyback transformer in which a resistor circuit for adjusting and setting a focus adjustment voltage is connected to a middle stage of a high voltage coil.

[0002]

2. Description of the Related Art FIG. 3 shows a circuit of a general flyback transformer in which a high voltage coil is laminated.
In the figure, a low-voltage coil 2 is fitted to a core 1, and a high-voltage coil 3 is fitted outside the low-voltage coil 2.

The high voltage coil 3 is formed by laminating the coil portions 4a to 4e on the winding body of the high voltage bobbin via an insulating film such as polyester as an insulating layer.
A forward rectifier diode 5 for adding a voltage between the winding end of the coil 4d and the winding start of the coil portions 4b to 4e of the next layer;
a to 5d connected in series. The output terminal of the final coil section 4e is connected to the anode of a cathode ray tube (not shown) via a high voltage rectifier diode 6. The middle portion of the high pressure coil 3, the focus adjustment voltage terminal to the cathode side of the rectifier diode 5 b in the example of FIG. 3
9 is connected, and the resistance circuit of the focus pack 7 is connected to the middle stage of the high voltage coil 3 through the focus adjustment voltage terminal 9.
It is connected to. This resistance circuit has a focus adjustment resistor 8 and a screen adjustment resistor 10, and a focus adjustment voltage is set by slidingly adjusting a sliding terminal 11 of the focus adjustment resistor 8, and the setting is performed. The adjusted focus adjustment voltage is applied to the focus electrode of the cathode ray tube, and the screen adjustment voltage is set by slidably adjusting the sliding terminal 12 of the screen adjustment resistor 10, and the set screen adjustment voltage is set. The voltage is applied to the screen electrode of the cathode ray tube.

[0004]

Generally, when the brightness of the screen of the cathode ray tube changes from, for example, a dark screen to a bright screen, a high-voltage output current flows from the high-voltage coil 3 to the cathode-ray tube, and the high-voltage output voltage E _H drops. Phenomenon occurs.
In this case, the focus adjustment voltage E _F also high output voltage E _H
It changes following the change of. When the rate of change of ratio and focus adjustment voltage E _F of the change in the high output voltage E _H is equal, i.e., the focus is blurred when the focus adjustment voltage E _F is completely follow the change of the high output voltage E _H Although a good screen can be obtained without saying that, in actuality, each of the coil portions 4 a to 4
There are variations in the characteristics of the interlayer distribution capacity of the e, Accordingly, variations occur in the regulation characteristic of each layer of the coil portion 4 a to 4 e, followability of the focus adjustment voltage E _F to changes in the high-voltage output voltage E _H is poor becomes, as shown by the curve a in FIG. 2, it fluctuates ratio is large and the focus adjustment voltage E _F and high output voltage E _H by the magnitude of the high voltage output current and changes, for example from a bright screen to a dark screen, There is a problem that the focus is out of focus.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to improve the followability of a focus adjustment voltage with respect to a high-voltage output voltage and to achieve focus focusing by changing the luminance of a screen of a cathode ray tube. An object of the present invention is to provide a flyback transformer that does not blur.

[0006]

The present invention is configured as follows to achieve the above object. That is, the present invention is a high pressure coil is divided into a plurality of coil portions, a high pressure
Each coil portion is wound around the bobbin in a laminated manner via an insulating layer, and the winding end of the coil of each layer is connected to the winding start of the coil of the next layer via a forward rectifier diode that adds a pulse voltage. In a flyback transformer in which the focus adjustment voltage terminal is provided in the middle stage of the high-voltage coil, at least the focus adjustment voltage terminal is provided.
Between the upper coil side adjacent to the
The insulating layers formed between the metal parts differ in thickness or dielectric constant from each other.
And the rate of change of the focus adjustment voltage
The distance between the coil layers in the direction that follows the rate of output voltage change
It is characterized in that the cloth capacity is adjusted .

[0007]

In the present invention having the above structure, the distributed capacitance between the coil portions of the high-voltage coil constituting the flyback transformer is changed by changing the thickness of the insulating layer between the coil portions or the dielectric constant of the insulating layer. By consciously changing the distributed capacitance between the coil portions and adjusting the distributed capacitance of the high-voltage coil, the follow-up of the focus adjustment voltage with respect to the high-voltage output voltage is improved.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. In the description of the present embodiment, the same reference numerals are given to the same names as those in the conventional example, and detailed description thereof will be omitted. Configuration of one embodiment of a flyback transformer according to the present invention is shown in Figure 1. A characteristic of this embodiment is that the thickness of the insulating layer 13 between the coil portions 4a to 4c of the high voltage coil 3 and the thickness of the insulating layer 14 between the coil portions 4c to 4e are changed.
The coil section 4c provided with the focus adjustment voltage terminal 9 is
The boundary is that the interlayer distribution capacitance on the lower layer side is different from the interlayer distribution capacitance on the upper layer side, and the other configuration is the same as the conventional example. In this embodiment, the insulating layer 13 is formed of a 0.8 mm thick polyester film layer,
The insulating layer 14 is constituted by a polyester film layer having a thickness of 0.2 mm.

As described above, by changing the thickness of the insulating layers 13 and 14, the interlayer distribution capacitance between the lower coil portions 4a to 4c and the interlayer distribution capacitance between the upper coil portions 4c to 4e are consciously considered. Can be changed so that the high voltage coil 3
Varies in the overall distribution capacity of. The change in the distributed capacitance makes it possible to adjust the regulation characteristics of the high-voltage coil 3, and accordingly, the focus adjustment voltage E _F
Focus tracking properties for high output voltage E _H of can be improved.

A characteristic test of the follow-up property of the focus adjustment voltage using the high-voltage coil 3 of the present embodiment yielded a curve B in FIG. The focus tracking of the present embodiment As is apparent from the comparison with the curve A of the focus tracking of a conventional flyback transformer, a flyback transformer of the present embodiment the focus adjustment voltage E _F and high output voltage E _H
Is close to a substantially constant value with respect to the change in the high-voltage output current, and it can be seen that the focus following ability is greatly improved.

Therefore, according to the flyback transformer of this embodiment, it is possible to obtain a high-quality screen without defocusing due to a change in luminance of the screen of the cathode ray tube.

The present invention is not limited to the above embodiment, but can take various embodiments. For example, in the above embodiment, the focus adjustment voltage terminal 9 is connected to the coil unit 4c.
The thickness of the insulating layer between the lower coil portions 4a to 4c and the thickness of the insulating layer between the upper coil portions 4c to 4e are changed. It is necessary to change the thickness of the insulating layer between the coil portions of the respective layers in various modes other than the present embodiment.For example, in an extreme case, the thickness of the insulating layer between the coil portions of the respective layers can be changed. The thickness of each insulating layer can be different.

In the above embodiment, the film of the insulating layer is formed of the same material, and the dielectric constant of the film of each layer is the same. However, the thickness of the insulating layer between the coil portions of each layer is made the same, By changing the material of the insulating film between them and changing the dielectric constant, the distributed capacitance between the respective coil portions may be changed so that the distributed capacitance has the best focus followability. In general, the dielectric constant of a polyester film is 3.3 at a driving frequency of 1 KHz and a temperature of 25 ° C., and the dielectric constant of polyphenylene sulfide is the same under the same conditions.
3.0, and thus the dielectric constant will differ depending on the type of insulating film used as the insulating layer.By adjusting the dielectric constant of the insulating layer of each layer, a flyback transformer with excellent focus tracking can be obtained. .

[0014]

[Effect of the Invention] In the present invention, the high voltage coil is connected via a diode.
Into multiple coil sections, and each coil section
Through a high-pressure bobbin,
It is assumed that the focus adjustment voltage terminal is provided
And at least a coil with a focus adjustment voltage terminal
Between the upper coil side and the lower coil side adjacent to the
The formed insulating layers differ in thickness or dielectric constant from each other and
The rate of change of the focus adjustment voltage is the output voltage of the high-voltage coil.
The distributed capacitance between the coil layers in the direction that follows the rate of change
Since those where the structure has been adjusted, it is possible to improve the distributed capacitance to optimize the focus followability to high output voltage, thereby, due to the brightness change of the screen of a cathode ray tube focus It is possible to provide a flyback transformer of high image quality that does not cause out-of-focus blur.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing an example of a configuration of a high-voltage coil of a flyback transformer according to the present invention.

FIG. 2 is a graph showing the focus followability of the flyback transformer of the present embodiment in comparison with the focus followability of the conventional example.

FIG. 3 is a circuit diagram of a flyback transformer having a conventional general focus pack.

[Explanation of symbols]

 3 High voltage coil 4a ~ 4e Coil part 13,14 Insulation layer

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-187005 (JP, A) Jikken Sho 43-23238 (JP, Y1) Jikken Sho 49-9538 (JP, Y1) (58) Field (Int.Cl. ⁶ , DB name) H01F 38/42

Claims (1)

(57) [Scope of request for utility model registration] 1. A high-voltage coil is divided into a plurality of coil portions, and each coil portion is laminated and wound on a high-voltage bobbin via an insulating layer, and a winding end of each layer coil portion starts winding of a coil portion of the next layer. In a flyback transformer, which is connected to a terminal through a forward rectifier diode that adds a pulse voltage and is provided with a focus adjustment voltage terminal in a middle stage of a high voltage coil, a coil provided with at least a focus adjustment voltage terminal The insulating layer formed between the upper coil part and the lower coil part adjacent to the part differs in thickness or dielectric constant, and the rate of change of the focus adjustment voltage follows the rate of change of the output voltage of the high voltage coil. Characterized in that the distributed capacitance between the coil layers is adjusted in the direction of the flyback transformer.